cmd/evm: rename t8n args to improve clarity when tracing

[lightclient]

Apologizes for another PR - my new commits weren't coming through in #23933.

Okay I misunderstood the meaning of the args tracer.nomemory and tracer.noreturndata. I understand now that it is preferred that memory and return data are not printed by default. Given this, I think the flag name are confusing. I didn't realize until looking deeply into this that --tracer.nomemory=false is a valid argument. I would've assumed the flag did not take a value and was a simple on/off switch, and therefore assumed the correct default behavior for these values should be on. Others have also encountered this.

For these reasons, I propose renaming them to tracer.memory and tracer.returndata to avoid the double-negative flag tracer.nomemory=false.

[holiman]

Yeah, this is obviously the preferred approach, and we would have done that if we weren't so averse to making API changes. The "proper" way to do this is to have both flags in parallel for a while, and print an error message when the deprecated (nomemory) flag is used.

[lightclient]

Good point @holiman. I added the flags back and marked them as deprecated. I also decided to return an error if the flags are used in a conflicting manner. Not sure you handle situations in the past, but I can remove if you prefer.

[holiman]

Please add a printout whenever the deprecated flag is used, telling the user to use the new format instead.

[holiman]

LGTM

[WEEDAVIE1990]

cmd/evm/main.go